I selected non-continuous, above £18,600 and it’s then prompting me for 12 months of pay slips.
Does non-continuous mean off-and-on payments rather than continuous pay? Asking for 12 months pay tells me this might be the case
That's somewhat vague. Has your salary for the last 12 months been over the £18,600, and the employer the same? If so, then it might make sense to include a full year (possibly 13 months) of payslips to be sure.
1) I don’t have enough mail to specifically spread out every five months. What are my options?
Try to get as close as you can to those months. If it is a few days, perhaps even a couple of weeks apart, I would have thought it would be OK.
2) The accommodation requirement. We have our tenancy agreement but it’s expired and now we’re just on a sort of rolling lease with our landlord. Do I need additional evidence? It asks for evidence of monthly housing costs for the accommodation.
A letter from the landlord saying you have permission to stay along with the other information sounds like it would be sufficient.
3) Reasons to stay in UK. It asks the following ‘Do you have any other reasons for wanting to stay in the UK?(Required)
For example, include any information you wish to be considered about the welfare or best interests of any children you have in the UK. You must demonstrate you have a genuine, subsisting and active parental relationship.’
I'm under the impression this is what they would start to consider if you, say, didn't meet the financial requirement, so they can see if they might be able to put you on the 10 year route. If I were in your position I make a statement that you have that relationship with your child (I know this sounds silly!) - but between any correspondence between, say, a school, nursery, pre-school, GP, dentist, and your child (e.g. a letter of registration from the GP), along with birth certificates, and the aforementioned statement, that should cover it quite easily.
You could possibly well leave it blank. For our FLR(M)s we have done so.